Trim: 216 x 279 mm fm.indd 07/01/2015 Page ii Trim: 216 x 279 mm fm.indd 07/01/2015 Page i Basics of Dental Technology Trim: 216 x 279 mm fm.indd 07/01/2015 Page ii Trim: 216 x 279 mm fm.indd 07/01/2015 Page iii Basics of Dental Technology A Step by Step Approach Second edition Tony Johnson David G. Wildgoose PhD, MMedSci, LCGI, MCGI, FETC, FHEA MPhil, LCGI, MCGI, FETC Senior Lecturer Honorary Research Fellow School of Clinical Dentistry School of Clinical Dentistry Academic Unit of Restorative Dentistry Academic Unit of Restorative Dentistry University of Sheffield University of Sheffield UK UK David G. Patrick Duncan J. Wood PhD, PgDip, FHEA BMedSci, PhD, FHEA University Teacher Senior University Teacher School of Clinical Dentistry School of Clinical Dentistry Academic Unit of Restorative Dentistry Academic Unit of Restorative Dentistry University of Sheffield University of Sheffield UK UK Christopher W. Stokes BMedSci, PCHE, MEd, PhD, FHEA Senior University Teacher School of Clinical Dentistry Academic Unit of Restorative Dentistry University of Sheffield UK Trim: 216 x 279 mm fm.indd 07/01/2015 Page iv This edition first published 2016 © 2011, 2016 by John Wiley & Sons Ltd. Registered office: John Wiley & Sons, Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial offices: 9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK 1606 Golden Aspen Drive, Suites 103 and 104, Ames, Iowa 50010, USA For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley-blackwell The right of the author to be identified as the author of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. All rights reserved. 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No warranty may be created or extended by any promotional statements for this work. Neither the publisher nor the author shall be liable for any damages arising herefrom. Library of Congress Cataloging-in-Publication Data Johnson, Tony (Anthony Phillip), author. Basics of dental technology : a step by step approach / Tony Johnson, David G. Patrick, Christopher W. Stokes, David G. Wildgoose, Duncan J. Wood. -- Second edition. p. ; cm. Includes index. Preceded by Basics of dental technology / Tony Johnson . . . [et al.]. 2011. ISBN 978-1-118-88621-2 (pbk.) I. Patrick, David G., 1964- , author. II. Stokes, Christopher William, 1977- , author. III. Wildgoose, David G., author. IV. Wood, Duncan J., author. V. Title. [DNLM: 1. Technology, Dental--methods. 2. Technology, Dental--instrumentation. WU 150] RK652 617.6’9--dc23 2015006395 A catalogue record for this book is available from the British Library. Wiley also publishes its books in a variety of electronic formats. 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Cover image: background image - © Batke/Getty Images Set in 10/12pt Myriad Pro by SPi Global, Chennai, India 1 2016 Trim: 216 x 279 mm fm.indd 06/08/2015 Page v Contents About the Companion Website ix Chapter 1 INTRODUCTION 1 1.1 Introduction 1 1.2 How to use this book 1 1.3 Equipment and instruments 1 1.4 Health and safety in the dental laboratory 5 1.5 Sterilisation and impression handling 6 1.6 Introduction to model making 8 1.7 Models for prosthodontics – casting primary impressions 9 1.8 Models for prosthodontics – boxing-in impressions 12 1.9 Models for prosthodontics – casting working (secondary) impressions 13 1.10 Models for prosthodontics – models for cobalt–chromium frameworks 13 1.11 Orthodontic study models 14 1.12 Introduction to sectional models 16 1.13 Producing a sectional model using a tray system (Figure 1.13.1) 17 1.14 Producing a sectional model using a pinned system 19 1.15 Sectioning the model 20 1.16 Introduction to articulating models 22 1.17 Articulating models on a simple hinge articulator 22 1.18 Articulating dentate models using the average position 23 1.19 Articulating edentulous models using the average position 25 1.20 Articulating models using a facebow 26 Chapter 2 COMPLETE PROSTHETICS 31 2.1 Introduction to complete prosthetics 31 2.2 Construction of a close-fitting custom impression tray 32 2.3 Construction of a tray with spacer for edentulous cases 34 2.4 Construction of a tray for dentate or partially dentate cases 35 2.5 Construction of a windowed close-fitting tray 37 2.6 Construction of occlusal registration rims 38 2.7 Setting up denture teeth 42 2.8 Denture processing 47 2.9 Grinding and finishing the dentures 53 2.10 Denture repair 57 2.11 Relining a denture in the laboratory 60 2.12 Copy dentures 62 Chapter 3 PARTIAL PROSTHETICS 65 3.1 Introduction to partial prosthetics 65 3.2 Classification 65 Trim: 216 x 279 mm fm.indd 06/08/2015 Page vi 3.3 Component parts of partial dentures 66 3.4 Surveying 68 3.5 Designing partial dentures 71 3.6 Partial denture construction – acrylic resin 75 3.7 Partial denture construction – cobalt–chromium 77 Chapter 4 FIXED PROSTHODONTICS 85 4.1 Restoration design 85 4.2 Metal restorations 86 4.3 Ditching the die 88 4.4 Producing a wax pattern 88 4.5 Investing the wax pattern 90 4.6 Casting and de-vesting the pattern 92 4.7 Finishing the casting 94 4.8 Metal-ceramic restorations 98 4.9 Producing a wax pattern for a metal bonded to ceramic framework 99 4.10 Investing the wax pattern 102 4.11 Casting the pattern 102 4.12 De-vesting and surface preparation 104 4.13 Ceramic application and build-up 105 4.14 Ceramic restorations 112 4.15 Producing a high-strength ceramic substructure 114 4.16 Veneering a high-strength ceramic substructure 115 4.17 Producing a resin-bonded crown on a refractory die 115 4.18 Post crowns 117 4.19 Bridges 118 4.20 Producing a cast metal fixed–fixed restoration 121 4.21 Producing a soldered metal fixed–fixed restoration 122 4.22 Soldering 123 4.23 Minimal preparation bridges 125 4.24 Producing a minimal preparation bridge (Maryland technique) 126 4.25 Digital dentistry 128 4.26 Using a laboratory-based CAD–CAM system 131 4.27 Producing a posterior single-unit substructure or restoration using a reduction technique 132 4.28 Producing a bridge substructure 134 4.29 Removable Partial Denture Design 134 4.30 Implant-supported prosthodontics 139 Chapter 5 ORTHODONTICS 141 5.1 Introduction to orthodontics 141 5.2 Classification of malocclusions 142 5.3 Theory of tooth movement 143 5.4 Basic wire bending techniques 144 5.5 Making passive components 146 5.6 Producing ball-ended clasps 146 5.7 The Adams clasp 147 5.8 Producing a southend clasp 148 5.9 Active appliances 149 5.10 Palatal finger spring (guarded) 150 5.11 Making a T-spring 152 5.12 Double cantilever or Z-spring 152 vi Contents Trim: 216 x 279 mm fm.indd 06/08/2015 Page vii 5.13 Buccal canine retractor 153 5.14 The Roberts retractor 154 5.15 Producing baseplates 155 5.16 Producing biteplanes 156 5.17 Extra-oral anchorage 156 5.18 Functional appliance design 157 5.19 Producing an Andresen appliance 157 5.20 Twin-block appliance 158 5.21 Fixed orthodontic appliances 160 5.22 Retainer appliance design 160 5.23 Repair and modification of orthodontic appliances 162 5.24 Making tooth positioners 164 5.25 Sports Mouthguards 165 Chapter 6 OCCLUSION 167 6.1 Introduction to occlusion 167 6.2 Occlusal schemes 168 6.3 Articulators 170 6.4 Facebows 171 6.5 Summary 171 Chapter 7 SHADE, COLOUR AND SIZE DETERMINATION FOR DENTAL APPLIANCES 173 7.1 Introduction to aesthetics 173 7.2 Colour terminology 173 7.3 Shade guides 173 7.4 Selecting teeth for complete denture patients 175 Appendix TOOTH MORPHOLOGY 177 GLOSSARY 179 INDEX 181 Contents vii